Abstract
On the basis of hourly measurements of wind and air and sea surface temperatures for at least 6 yr at three buoy stations in the eastern Gulf of Mexico, the onset of the free convection regime, which coincides with the commencement of stability class C (for slightly unstable conditions in the Pasquill stability classification) at approximately Rb = −0.03, −Z/L = 0.4, and −Zi/L = 5, is verified over the ocean, where Rb is the bulk Richardson number, Z (= 10 m) is the height above the sea, L is the Monin–Obukhov stability length, and Zi is the height of the convective boundary layer (CBL). Datasets for the CBL are analyzed in the context of the boundary layer physics of Garratt. It is found that Zi is linearly proportional to the surface buoyancy flux—that is, (
Corresponding author address: Dr. S. A. Hsu, Coastal Studies Institute, Louisiana State University, 308 Howe/Russell Geoscience Complex, Baton Rouge, LA 70803-7527.